1. Field of the Invention
The present invention relates to a composition for removing photoresist, a method of removing photoresist and a method of manufacturing a semiconductor device using the same.
2. Description of the Related Art
In a semiconductor manufacturing process, an integrated circuit is generally formed using a photolithography process. Photoresist used in the photolithography process may be denatured in a plasma etching process to form a polymer that is not easily removed from a substrate. The polymer includes photoresist residues, organic impurities or etching residues generated in the plasma etching process. The plasma etching residues are largely formed on sidewalls of a pattern and thus are not easily removed by a cleaning solution for removing photoresist.
Cleaning solutions including hydroxylamine or a fluorinated compound have been used for conventional semiconductor cleaning processes. For example, a cleaning solution including a fluorinated compound is disclosed in Japanese Laid-Open Patent Publication No. 2004-29346. The cleaning solution includes a strong nucleophilic compound. The nucleophilic compound easily decomposes a denatured polymer. The cleaning solution may decompose and dissolve the denatured polymer and plasma etching residues regardless of the types of photoresist used in the photolithography process.
Recently, various types of metal have been introduced in a semiconductor manufacturing process, and patterns of the integrated circuit have been formed using the metal. However, the cleaning solutions may not remove a composite of metal and polymer, and/or the cleaning solutions may corrode metal patterns. Further, the cleaning solutions may not be used in a process that requires selective removal of photoresist. For example, the cleaning solutions may not be applied in a color filter manufacturing process for a CMOS image sensor (CIS), because the cleaning solutions may remove all types of photoresist nonselectively, including photoresist that constitutes a lens of the color filter.
A photoresist stripping composition including alkanolamine, a sulfone compound, a sulfoxide compound, etc. is disclosed in Japanese Laid-Open Patent Publication No. 1992-350660. A photoresist stripping composition including N-alkanolamine is disclosed in Japanese Laid-Open Patent Publication No. 1996-87118. The photoresist stripping compositions have relatively good photoresist removability and good composition stability. However, as process conditions increase in magnitude, the photoresist stripping compositions may not completely remove photoresist. For example, when the process temperature is higher than about 120° C., the photoresist may be post-baked or severely denatured. Thus, the severely denatured photoresist may not be completely removed by the photoresist stripping compositions.
A ketone-based cleaning solution has been used for removing specific photoresist in a color filter manufacturing process for a CIS. The ketone-based cleaning solution has a strong dissolving ability for photoresist. However, the ketone-based cleaning solution may not dissolve the denatured photoresist completely and the ketone-based cleaning solution may not selectively remove a particular type of photoresist. In addition, the ketone-based cleaning solution has a high volatility, and thus, when a processing wafer is moved for performing a subsequent process, undissolved photoresist may be readsorbed onto the processing wafer. The readsorbed photoresist may cause a processing failure in a subsequent process.
Therefore, it would be highly desirable to have a composition that has excellent photoresist removability, and also selectively removes a particular type of photoresist.